The ocean covers more than 70% of earth surface. Under different moon's gravities during different time periods, the sea water in the ocean produces rising tide and falling tide twice from day to day, with tidal difference ranging from 2-6 meter and even more than 10 meters. In addition, varying fluctuation wave is also produced. Such tide and wave can generate tremendous energy.
In the tidal power generation of the prior art, shrinkage water channel is utilized to introduce the oceanic wave on the tide to the elevated reservoir to form head of water (water head), and the down flow of water head is utilized to directly drive the water-turbine generator set to generate power. As a result, very little tidal energy is used in power generation.
Wind wave can be generated when wind acting on sea water, and surge can be caused by earthquake and volcanic explosion at sea bottom. As a result, the oceanic wave energy is the most abundant, inexhaustible, polar and reliable energy resources in the earth, while wave energy also accounts for major weight in ocean energy sources. The wave motion of sea water can generate enormous energy in the forms of up-and-down, backwards and forwards, left and right fluctuation, sloshing and swarming of sea water. According to estimation, the wave energy that can be easily utilized in the world's ocean is more than 100 billion KW.
The tidal energy and wave energy are the cleanest renewable resources. With the development and utilization of tidal energy and wave energy, it is feasible to basically eliminate the energy crisis due to the gradual drain of mineral energy and to improve the environmental damage resulted from the burning of mineral energy.
In the past, the oceanic wave energy and tidal energy as always regarded as a disordered, dispersed, interrupted, uncontrollable, low-speed and low-grade mechanical energy, which can only be utilized unless it has been turned into orderly, concentrated, continuous, controllable and high speed energy through intermediate links.
For the past century, the scientists all over the world have made unremitting endeavors to put forward hundreds of assumptions and invent various devices for utilizing oceanic wave energy for power generation. At present, in addition to said tidal power generation device, the comparatively mature wave power generation devices are also divided into the following two major types:
One is “wave-compressed air type”. A container device with fixed volume, which is communicated with the sea water, is adopted; the changes in the water surface position generated by the waves cause the changes in the air volume in the container; with the air in the compression container as intermediate agent, the compressed air is used to drive the impeller, which in turn drives the power generation system to generate power;
The second is “mechanical drive liquid type”. The movement of oceanic wave is used to push the movable mechanical parts of intermediate device, such as duck body, raft body and floater, the movable mechanical parts drive intermediate agent, such as oil or water, to push the power generation system to generate power.
It is difficult for other types of mechanical energy conversion devices to achieve continuous, stable, concentrated and controllable energy with even rate, so that they are less applied.
Although three types of wave power generation devices have their respective advantages, they have common disadvantages as follows: 1. Multiple intermediate links for converting oceanic wave energy to electric energy, complex equipment, low efficiency, not easy to form large-scale power generation; 2. Only one-dimension energy in the mechanical energy of oceanic wave can be partially utilized, and it is impossible to absorber the disordered, dispersed, low-density and unstable three-dimensional wave energy, leading to higher power-production cost; 3. The oceanic wave energy conversion devices and their structures have poor ability to withstand catastrophic maritime climates, so that it is not easy to resist the damages from typhoon and tsunami, causing major potential safety hazards. This is a major problem in the development and utilization of oceanic wave energy at present.
Recently, a floating type sea snake technology has been developed in western European countries, including UK. Several floats connected in series are used to ride on the oceanic wave and utilizes the changes in the undulating angles of oceanic wave to impel the pistons of floats for power generation. Such mode can indeed enhance the wind and wave resistance of system. However, in fact the fluctuation of water wave is very gentle with very small angular change, and it is perpendicular to the wave peak line. Therefore, a string of floats can only correspond to the water wave with very small width. As a result, such floating type sea snake technology can not produce ideal efficiency and sufficient strong ability for resisting typhoon and tsunami, failing to overcome said problem.
As a result of different kinds of technical problems, the cost of wave power generation is 10 times higher than that of thermal power generation, and there are also potential safety hazards in the field.
More complex science and technology does not mean better effect. On the contrary, it is high-tech that can use the most simple equipment and method to overcome the problem that has been regarded as being difficult to address. To improve the practical effect of wave power generation, it is necessary to address the major problems in the prior art, slip the leash from traditional concept, reduce the intermediate links, utilize simple but convenient and reliable equipment to adapt to the actual conditions of oceanic wave movement and thus to realize the conversation of three-dimensional energy produced by oceanic wave.